Method of and apparatus for removing oil from a waste object

ABSTRACT

A waste object containing oil has a first opening formed therein at an upper portion thereof and a second opening positioned below the first opening. The first and second openings are connected to a recovery tank. Hot water of a predetermined temperature is held in the recovery tank and is caused to accumulate inside the waste object via the second opening. Oil that has floated upwards is recovered in the recovery tank via the first opening.

BACKGROUND OF THE INVENTION

[0001] (Field of the Invention)

[0002] The present invention relates to a method of removing oil asimplemented prior to the breaking or dismantling of industrial wasteobjects containing oil, such as compressors, engines, or the like, andto an apparatus for effecting the same.

[0003] (Description of the Related Art)

[0004] Conventionally, after an industrial waste object made from iron,plastic or a combination of these, etc. has been broken up using abreaking machine, or the like, it is recycled by separation andclassification.

[0005] Since waste objects such as compressors, engines, or the likecontain oil, there is a danger of the oil catching fire and exploding ifthey are put directly into a breaking machine in this state. Thus, ithas only been possible to break up such products by low-temperaturebreaking in an inert gas atmosphere, which entails expensive apparatusand running costs. In general, it has been common to use manualdismantling by fusing, which is inexpensive but dangerous.

[0006] However, the manual dismantling by fusing generates flames andinvolves the danger of fire or burns, the ambient atmosphere is degradedby production of smoke, and there are also limits on the processingcapacity of the operator. Accordingly, it has been necessary previouslyto remove oil from waste objects in an efficient manner, in order thatthey can be processed safely using a breaking machine, or the like.

SUMMARY OF THE INVENTION

[0007] The present invention has been developed to overcome theabove-described disadvantages.

[0008] It is accordingly an objective of the present invention toprovide a method of and an apparatus for removing oil from industrialwaste objects, whereby dismantling can be carried out safely withoutpolluting the ambient environment, by removing oil efficiently fromindustrial products containing oil, prior to dismantling of the same ina breaking machine, or the like.

[0009] In accomplishing the above and other objectives, a methodaccording to the present invention comprises the steps of: attaching anoil recovery vessel to a first opening provided in an upper portion of awaste object containing oil; injecting water into the waste object via asecond opening positioned below the first opening, thereby causing waterto accumulate inside the waste object and causing the oil inside thewaste object to float upwards; and recovering the oil that floatsupwards in the oil recovery vessel.

[0010] Hot water, cleaning solution or water at room temperature ispreferably used as water to be injected into the waste object to reducethe viscosity of oil contained therein or soften oil adhering thereto.

[0011] Advantageously, the second opening is connected to a recoverytank, and after oil has been recovered in the oil recovery vessel, theoil and water lying above the second opening is recovered in therecovery tank.

[0012] Conveniently, at least one of the first and second openings is athrough-hole formed in the waste object.

[0013] Another form of the present invention is a method comprising thesteps of: connecting a recovery tank to a first opening provided in anupper portion of a waste object containing oil and to a second openingpositioned below the first opening; injecting water of a predeterminedtemperature held in the recovery tank into the waste object via thesecond opening, thereby causing water to accumulate inside the wasteobject and causing the oil inside the waste object to float upwards; andrecovering the oil that floats upwards in the recovery tank via thefirst opening.

[0014] Advantageously, after oil has been recovered in the recoverytank, the oil and water lying above the second opening is recovered inthe recovery tank via the second opening.

[0015] Conveniently, the first opening is connected to a vacuum pump,and the inside of the waste object is reduced to low pressure beforewater is injected into the waste object.

[0016] Again conveniently, the first opening is connected to acompressed air source, and after oil has been recovered in the recoverytank, the oil and water lying above the second opening is recovered inthe recovery tank by supplying compressed air to the inside of the wasteobject.

[0017] A further form of the present invention is a method comprisingthe steps of: connecting a heated fluid source and a recovery tank,respectively, to a first opening and a second opening provided in awaste object containing oil; causing the oil inside the waste object toflow out via the second opening, by supplying a heated fluid to theinside of the waste object via the first opening; and recovering the oildischarged from the second opening in the recovery tank.

[0018] It is preferred that steam be used as the heated fluid. In thiscase, condensate of steam supplied to the inside of the waste object iscaused to accumulate inside the waste object.

[0019] Heated air may be used as the heated fluid. In this case, thesecond opening is provided at the lowest point of the waste object, andoil inside the waste object, which has been reduced in viscosity by theheated air, is recovered in the recovery tank under its own weight.

[0020] An apparatus according to the present invention includes arecovery tank connected to a first opening formed in an upper portion ofa waste object and to a second opening positioned below the firstopening, a first pipe connecting the first opening to the recovery tankvia a first valve, a second pipe connecting the second opening to therecovery tank via a second valve, a pump provided in the second pipe,and a controller for controlling the first and second valves and thepump.

[0021] By this arrangement, when the second valve is opened and the pumpis actuated, water of a predetermined temperature contained in therecovery tank is injected into the waste object via the second openingto accumulate inside the waste object, thereby causing the oil in thewaste object to float upwards. Such oil is recovered in the recoverytank via the first opening by opening the first valve.

[0022] Advantageously, the apparatus further includes a third pipeconnecting the second opening and the recovery tank via a third valve,wherein after oil has been recovered in the recovery tank, the oil andwater lying above the second opening is recovered in the recovery tankby opening the third valve.

[0023] Again advantageously, the apparatus further includes a vacuumpump connected to the first opening via a fourth valve, wherein beforeinjecting water into the waste object, the inside of the waste object isreduced to low pressure by opening the fourth valve.

[0024] The apparatus may include a compressed air source connected tothe first opening via a fifth valve, wherein after the oil has beenrecovered in the recovery tank, the oil and water lying above the secondopening is recovered in the recovery tank by opening the fifth valve tosupply compressed air to the inside of the waste object.

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The above and other objectives and features of the presentinvention will become more apparent from the following description ofpreferred embodiments thereof with reference to the accompanyingdrawings, throughout which like parts are designated by like referencenumerals, and wherein:

[0026]FIG. 1 is a front view of a sealed compressor used as a workexample;

[0027]FIG. 2 is a piping system diagram of an oil removing apparatusaccording to a first embodiment of the present invention;

[0028]FIG. 3 is a timing chart of a case where oil removal is carriedout using the oil removing apparatus of FIG. 2;

[0029]FIG. 4 is a diagram similar to FIG. 2, but according to a secondembodiment of the present invention;

[0030]FIG. 5 is a block diagram illustrating the control of the oilremoving apparatus of FIG. 4;

[0031]FIG. 6 is a timing chart of a case where oil removal is carriedout using the oil removing apparatus of FIG. 4;

[0032]FIG. 7 is a diagram similar to FIG. 2, but according to a thirdembodiment of the present invention;

[0033]FIG. 8 is a timing chart of a case where oil removal is carriedout using the oil removing apparatus of FIG. 7;

[0034]FIG. 9 is a diagram similar to FIG. 2, but according to a fourthembodiment of the present invention; and

[0035]FIG. 10 is a timing chart of a case where oil removal is carriedout using the oil removing apparatus of FIG. 9.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0036] This application is based on an application No. 10-215209 filedJul. 30, 1998 in Japan, the content of which is incorporated hereinto byreference.

[0037]FIG. 1 shows a sealed compressor W forming an industrial wasteobject, which includes a sealed container 2 holding an electric motorand compressor elements, and a gas-liquid separator 4 juxtaposed withthe sealed container 2. The gas-liquid container 4 is coupled to aninlet pipe 6, and the sealed container 2 is coupled to a discharge pipe8. The sealed compressor W contains oil for lubricating the compressorelements during operation, and if the sealed compressor W were to beintroduced into a breaking machine in this state, there is a danger thatthe oil would catch fire and explode.

[0038] The implementation of the method of removing oil according to thepresent invention is described below, using the sealed compressor Whaving the foregoing composition as a work example.

[0039] Embodiment 1

[0040]FIG. 2 shows an oil removing apparatus according to a firstembodiment of the present invention, and FIG. 3 is a timing chart of acase where oil is removed.

[0041] As shown in FIG. 2 and FIG. 3, the work W is first set andclamped (fixed) in a predetermined position, and a through-hole 10 of φ6-8, for example, is formed by drilling, punching, or the like, in anupper portion of a cylindrical shell forming the sealed container 2,which is a part of the work W. Thereupon, an oil recovery drum 14 havinga valve 12 is connected to the discharge pipe 8, and an oil and hotwater recovery tank 18 accommodating a heater 16 and positioned in thevicinity of the work W is connected via pipes 20, 22 to the through-hole10 in the sealed container 2. A hot water pump 24 and a valve 26 areinstalled on the course of the pipe 20, while a valve 28 is installed onthe course of the pipe 22. A level sensor 30 is attached to the oilrecovery drum 14 for detecting the level of hot water or oil containedtherein.

[0042] The heater 16 is already switched on prior to the formation ofthe through-hole 10 in the sealed container 2, and water previouslystored in the oil and hot water recovery tank 18 is heated to apredetermined temperature by means of ON/OFF control by a thermostat(not shown).

[0043] In this state, an opening of the inlet pipe 6 is closed and thevalve 12 is opened. After a predetermined time period T1 has passed, thevalve 26 is opened and the hot water pump 24 is actuated, whereupon thehot water held at the predetermined temperature by the heater 16 passesfrom the oil and hot water recovery tank 18 to the sealed vessel 2. Whenthe water has passed and is detected by the level sensor 30 that the hotwater or oil inside the oil recovery drum 14 has reached a predeterminedlevel, the hot water pump 24 is halted and the valve 26 is closed.

[0044] If this state is maintained for a predetermined time period T2(for example, 1 second-10 seconds), then practically all of the oilremaining in the sealed container 2 will be heated by the hot water andthe viscosity thereof will fall (it will become more fluid), and hencethe oil will gradually float upwards in the sealed container 2, beingrecovered in the oil recovery drum 14 and accumulating in the upperportion thereof.

[0045] After a predetermined time period T2 has elapsed, the valve 12 isclosed, and the oil recovery drum 14 is separated from the sealedcontainer 2, whilst the valve 28 is opened for a predetermikned timeperiod T4 such that the hot water located above the through-hole 10 andcontaining a quantity of oil is recovered in the oil and hot waterrecovery tank 18.

[0046] The oil inside the oil recovery drum 14 separated from the sealedcontainer 2 is further separated into an oil component and watercomponent by an oil/water separating device (not shown), via a recoverydevice (not shown). The separated oil component is further deaerated bya vacuum deaeration device, dust and moisture is separated therefrom,and it is then reused as lubricating oil, fuel oil, or the like.

[0047] The hot water in the upper portion of the through-hole 10 isrecovered in the oil and hot water recovery tank 18. After the valve 28is closed, the work W which is filled with water is removed andintroduced into a breaking machine. Since almost all of the oil isremoved from the work W and the work W is filled with water, temperaturerise during breaking is suppressed and there is no danger of fire orexplosion.

[0048] Embodiment 2

[0049]FIG. 4 shows an automated apparatus for extracting oil accordingto a second embodiment of the present invention.

[0050] In the oil extracting apparatus illustrated in FIG. 4, since theposition in which the through-hole 10 is formed and the connectionrelationship between the work W and the oil and the hot water recoverytank 18 are the same as those in the oil extracting apparatusillustrated in FIG. 2, only the points of difference are describedbelow.

[0051] A discharge pipe 8 attached to a sealed container 2 is connectedrespectively, via a pipe 36 and pipe 38, to a vacuum pump 32 andcompressed air source 34. A valve 40 and oil recovery tank 42 areinstalled on the course of the pipe 36, while a valve 44 is installed onthe course of the pipe 38. The discharge pipe 8 is also connected via apipe 46 to an oil and hot water recovery tank 18. A valve 48 isinstalled in the pipe 46, and a hot water detector 50, such as a reedswitch, is installed between the valve 48 and discharge pipe 8.

[0052] In FIG. 4, numeral 52 is a compressed air pressure detectorattached to the pipe 38, numeral 54 is a vacuum state detector attachedto the oil recovery tank 42, and numeral 56 is a hot water temperaturedetector attached to the oil and hot water recovery tank 18.

[0053] As shown in FIG. 5, a heater 16 provided in the oil and hot waterrecovery tank 18, a hot water pump 24, vacuum pump 32, valves 26, 28,40, 44, 48 and various detectors 50, 52, 54, 56 are connectedelectrically to a controller 58, which performs various controloperations.

[0054] Next, the action of the oil removing device in FIG. 4 isdescribed with reference to the timing chart illustrated in FIG. 6.

[0055] Similarly to the first embodiment, the work W is first set andclamped in a predetermined position, and a through-hole 10 of φ 6-8, forexample, is made by drilling, punching, or the like, in the upperportion of the cylindrical shell forming the sealed container 2.Thereupon, the pipe 36 leading to the vacuum pump 32, the pipe 38leading to the compressed air source 34, and the pipe 46 leading to theoil and hot water recovery tank 18 are connected to the discharge pipe8. The oil and hot water recovery tank 18 is connected to thethrough-hole 10 in the sealed container 2 via pipes 20 and 22.

[0056] The heater 16 is already switched on prior to formation of thethrough-hole 10 in the sealed container 2, and the water inside the oiland hot water recovery tank 18 is heated by the heater 16 and thetemperature thereof is detected by a hot water temperature detector 56.A signal indicating the detected temperature is transmitted to thecontroller 58 and the water in the oil and hot water recovery tank 18 isheld at a predetermined temperature (for example, 50-65° C.) by means ofthe controller 58 performing ON/OFF control of the heater 16 on thebasis of the temperature signal.

[0057] On the other hand, the oil recovery tank 42 is reduced to avacuum by the vacuum pump 32, and when the vacuum state detector 54detects a predetermined vacuum state after the pipe connections to thework W have been established, it transmits a signal to this effect tothe controller 58, which causes the valve 40 to open.

[0058] After a predetermined time period T1 (for example, severalseconds,) has elapsed, the valve 40 is closed, and simultaneously withthis, the hot water pump 24 is activated and the valve 26 is opened.Thereupon, since the work W is in a reduced pressure state, hot watersupplied from the oil and hot water recovery tank 18 by means of the hotwater pump 24 accumulates rapidly inside the work W. When hot wateraccumulates inside the work W, the viscosity of the oil remaining insidethe work W is reduced by the hot water, this oil gradually floatsupwards. When the hot water detector 50 confirms that hot water or oilis overflowing from the work W, it transmits a signal to this effect tothe controller 58, which causes the valve 48 to open.

[0059] When the valve 48 is opened, the oil which has been reduced inviscosity and has become more fluid is recovered in the oil and hotwater recovery tank 18 via the valve 48. When a predetermined timeperiod T2 (for example, several seconds) has elapsed after opening thevalve 48, both the valve 48 and valve 26 are closed, and the hot waterpump 24 is halted. In this state, if the compressed air pressure asdetected by the compressed air pressure detector 52 is above apredetermined value (for example, 3.5 kg/cm²), then the detector 52sends a signal to this effect to the controller 58, which causes thevalve 44 and valve 28 to open. Consequently, the hot water containingoil accumulated in the portion of the work above the through-hole 10 isrecovered rapidly in the oil and hot water recovery tank 18 via thevalve 28 under the pressure of the compressed air supplied via the valve44. Once the valve 44 has been opened for a predetermined time periodT3, it is closed and after a further predetermined time period T4 haselapsed, the valve 28 is closed.

[0060] Thereupon, the work W containing water in the portion thereofbelow the through-hole 10 is detached and introduced into a breakingmachine.

[0061] Similarly to the first embodiment, the oil recovered in the oiland hot water recovery tank 18 is further separated into an oilcomponent and water component by an oil-water separating device, via arecovery device. The separated oil component is further deaerated bymeans of a vacuum deaeration device, and dirt and moisture are removed,whereupon it is reused.

[0062] In the embodiment described above, the vacuum pump 32, compressedair source 34, and associated piping are not specifically necessary, andthese elements may be omitted.

[0063] Moreover, in this embodiment and the first embodiment, hot waterwas used as the recycling water, but it is also possible to use acleaning solution containing a cleaning agent at a predeterminedtemperature. If the ambient temperature is high, then the cleaningsolution or water at room temperature may be used directly withoutheating.

[0064] Moreover, the position of the through-hole 10 was set in theupper portion of the cylindrical shell forming the sealed container 2,but the through-hole may also be provided in another position, providedthat this position allows a certain amount of water to accumulate insidethe sealed container 2. It is also possible to provide two or morethrough-holes in the sealed container 2, sealing off the discharge pipe8 and connecting the pipes 20, 22, 36, 38, 46 independently.Furthermore, rather than providing any through-holes, it is alsopossible to utilize the openings of the inlet pipe 6 and the dischargepipe 8.

[0065] Embodiment 3

[0066]FIG. 7 shows an oil removing apparatus according to a thirdembodiment of the present invention, and FIG. 8 is a timing chart of anoil removing process.

[0067] As illustrated in FIG. 7 and FIG. 8, a work W is first set andclamped in a predetermined position, and a through-hole 10 of φ 6-8 isformed by drilling, punching, or the like, in a lower portion of thecylindrical shell, which forms a part of the work W. Thereupon, a steamsupply source 60 is connected via a pipe 62 to a discharge pipe 8, and apipe 64 forms a branching junction along the course of pipe 62. A valve66 is attached to the pipe 62 and a valve 68 connected to the air isattached to the pipe 64.

[0068] On the other hand, an oil and hot water recovery tank 18 providedin the vicinity of the work W is connected to the through-hole 10 in thesealed container 2 via a pipe 70. The opening of the inlet pipe 6 issealed off.

[0069] In this state, if steam is supplied into the work W from thesteam supply source 60 by opening the valve 66, whilst also openingvalve 72, then the oil remaining inside the work W will be heated by thesteam, the viscosity thereof will fall, and the oil will accumulate in abottom portion of the work W. When valve 66 has been held open for apredetermined time period T1, a portion of the steam will condense,forming hot water, which accumulates in the lower portion of the work Wwith the oil. Consequently, the oil floats to the top of the hot water,and is recovered in the oil and hot water recovery tank 18 via the pipe70.

[0070] When a predetermined time period T1 has elapsed, the valve 66 isclosed and the valve 68 is opened, thereby allowing the oil to continueto be recovered in the oil and hot water tank 18, whilst releasing thepressure inside the work W externally, via the valve 68. When the valve72 has been opened for a predetermined time period T2, it is closedalong with the valve 68.

[0071] The pipes 62, 64 are then detached from the discharge pipe 8 andthe pipe 70 is removed from the through-hole 10, whereupon the work W isintroduced into a breaking machine.

[0072] The subsequent processing of the oil recovered from the oil andhot water recovery tank 18 is similar to that in the first and secondembodiments, and hence description thereof is omitted here. Moreover, itis also possible to provide two or more through-holes in the sealedcontainer 2, the discharge pipe 8 being sealed off and the pipes 62, 64and 70 being connected independently. Moreover, rather than providingany through-holes, it is also possible to utilize the openings of theinlet pipe 6 and the discharge pipe 8. Furthermore, instead of steam,pressurized hot water or cleaning solution may be used, and if theambient temperature is high, pressurized water at room temperature maybe used.

[0073] In the present embodiment, since the work W contains accumulatedwater when it is introduced into a breaking machine, there is littletemperature rise during breaking, and since the oil content thereof issmall, there is little danger of fire or explosion.

[0074] Embodiment 4

[0075]FIG. 9 shows an oil removing apparatus according to a fourthembodiment of the present invention, and FIG. 10 is a timing chart of anoil removing process.

[0076] This embodiment is similar to the third embodiment, but differstherefrom in that heated air or steam is used as a medium to be suppliedto the work W and in that a through-hole 10 is formed in the center ofthe lower part of the shell (lowest point).

[0077] Therefore, in the present embodiment, there is no accumulation ofwater in the work W and the oil is recovered in the oil and hot waterrecovery tank 18 under its own weight. The further composition andaction of this embodiment is the same as the third embodiment, and hencedescription thereof is omitted here. Moreover, instead of heated air orsteam, it is possible to use pressurized hot water or cleaning solution.If the ambient temperature is high, then pressurized water at roomtemperature may be used. It is also possible to provide two or morethrough-holes in the sealed container 2, the discharge pipe 8 beingsealed off and the pipes 62, 64 and 70 being connected independently.

[0078] The first to fourth embodiments described above related to a casewhere a sealed compressor was used as the work W, but the presentinvention can of course be applied to other sealed objects containingoil, such as engines, or the like.

[0079] Being constituted as described above, the present invention hasthe following merits.

[0080] According to the first aspect of the present invention, water iscaused to accumulate inside the waste object by injecting water via asecond opening positioned below the first opening, and the oil thatfloats upwards is recovered in an oil recovery vessel via the firstopening. Accordingly, the oil is gathered reliably into the oil recoveryvessel, the oil becoming separated from the water due to the differencein specific gravity, and hence oil can be recovered with goodefficiency.

[0081] Moreover, since a second opening is connected to the recoverytank, and after the oil has been recovered, the oil and water lyingabove the second opening is recovered in the recovery tank, virtually nooil remains in the waste object prior to dismantling. Thus, the wasteobject can be dismantled safely.

[0082] Furthermore, since a through-hole formed in the waste object isused for at least one of the first and second openings, it is possibleto set the amount of water accumulating inside the waste objectaccording to the position in which the through-hole is formed, and hencetemperature rise during dismantling of the waste object can besuppressed appropriately.

[0083] Also, since water is caused to accumulate inside the waste objectby injecting the water in the recovery tank via the second opening,whilst the oil that has floated upwards is recovered in the recoverytank via the first opening, it is possible to effectively recover oilthat has been separated from the water due to the specific gravitydifference, without ambient dispersal of oil.

[0084] Moreover, since the inside of the waste object is reduced to alow pressure before injecting water into the waste object, wateraccumulates rapidly therein and oil recovery can be carried out withgood efficiency.

[0085] Also, after oil has been recovered, the oil and water lying abovethe second opening is recovered rapidly in the recovery tank bysupplying compressed air to the inside of the waste object. It is,therefore, possible to raise the efficiency of oil recovery and increasethe safety of dismantling.

[0086] If a heated fluid is supplied to the inside of the waste objectvia the first opening to reduce the adhesion of the oil inside the wasteobject and to make the oil more fluid, it is possible to recover oilreliably, without contaminating the ambient atmosphere, using a simplecomposition.

[0087] Furthermore, since steam is used as a heated fluid and watercondensed from the steam supplied to the waste object accumulates insidethe waste object, it is possible to suppress temperature rise duringdismantling of the waste object.

[0088] The oil inside the waste object can be recovered in the recoverytank under its own weight by reducing the viscosity thereof using heatedair. In this case, oil recovery can be effectively carried out in anextremely simple manner.

[0089] In the oil recovering apparatus according to the presentinvention, when a second valve is opened and a pump is actuated, waterin a recovery tank is caused to accumulate inside the waste object via asecond opening and to float upwards. When a first valve is opened, theoil that has floated upwards is recovered in the recovery tank via afirst opening. Accordingly, it is possible to recover oil which has beenseparated from water by means of their difference in specific gravity,efficiently, without oil being dispersed into the ambient environment.

[0090] Furthermore, since the oil and water lying above the secondopening is recovered in the recovery tank by opening a third valve,after oil has been recovered, virtually no oil remains in the wasteobject before dismantling. It is, therefore, possible to dismantle thewaste object safely.

[0091] Moreover, since the internal pressure of the waste object isreduced by opening a fourth valve before causing water to accumulateinside the waste object, it is possible to fill water into the wasteobject rapidly, and hence oil recovery can be carried out efficiently.

[0092] Also, after oil has been recovered, the oil and water lying abovethe second opening is recovered rapidly by supplying compressed air tothe inside of the waste object by opening a fifth valve. Accordingly, itis possible to achieve good efficiency of oil recovery and safedismantling of the waste object.

[0093] Although the present invention has been fully described by way ofexamples with reference to the accompanying drawings, it is to be notedhere that various changes and modifications will be apparent to thoseskilled in the art. Therefore, unless such changes and modificationsotherwise depart from the spirit and scope of the present invention,they should be construed as being included therein.

What is claimed is:
 1. A method of removing oil from a waste object,comprising the steps of: connecting a heated fluid source to one of afirst opening and a second opening provided in a waste object containingoil, said second opening being positioned below said first opening;connecting a recovery tank to the other of said first opening and saidsecond opening in the waste object; injecting a fluid medium from theheated fluid source into the waste object via said one of the first andsecond openings, thereby reducing the viscosity of the oil in the wasteobject; and recovering the oil discharged from the other of the firstand second openings in the recovery tank.
 2. The method according toclaim 1 , wherein the heated fluid source is the recovery tank, and thefluid medium is heated water contained in the recovery tank.
 3. Themethod according to claim 1 , wherein the fluid medium is s team from asteam supply source.
 4. The method according to claim 1 , wherein thefluid medium is heated air from a heated air source.